TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1861 SUBJECT: GRB 030204: Optical Observations DATE: 03/02/07 18:25:09 GMT FROM: Melissa Nysewander at UNC,Chapel Hill M. Nysewander (U. North Carolina), A. Henden (USRA/USNO), M. Lopez-Morales, D. Reichart (U. North Carolina), and M. Schwartz (Tenagra Observatories) report on behalf of a larger collaboration: We observed the entire ~73 square arcminute error box of GRB 030204 (GCN 1854) beginning 11.5 hours after the burst (GCNs 1856, 1858) in BVRcIc and beginning 38.2 hours after the burst in Rc. Using the field calibration of Henden (GCN 1860), we report the following 3-sigma limiting magnitudes: Date Mean Time Filter Integration Limiting Telescope* Since GRB Time (sec) Magnitude (hours) x Pointings Feb 5.011 11.5 Rc 1500 x 3 20.0 0.6-meter MO Feb 5.042 12.2 Ic 3600 x 1 19.3 0.2-meter PST Feb 5.108 13.8 Rc 900 x 2 21.5 1.0-meter USNO Feb 5.133 14.4 B 480 x 2 22.0 1.0-meter USNO Feb 5.133 14.4 V 300 x 2 21.7 1.0-meter USNO Feb 6.122 38.2 Rc 1800 x 2 22.9 1.0-meter USNO Feb 6.124 38.2 Rc 2700 x 2 21.7 0.8-meter TII *MO = Morehead Observatory telescope; PST = Pisgah Survey Telescope at the Pisgah Astronomical Research Institute (PARI); TII = Tenagra II telescope. Using the image subtraction routine ISIS2 (Alard 2000), we find no transient sources in either of our Rc images of February 4th when compared to either of our Rc images of February 5th. Alard, C. 2000, A&AS 114, 363